Which Tubes In Your HX/DA???

One-off point-to-point build (2 x 12AX7 pre amp, 1 x 12AX7 phase inverter, 2 x EL34's) with lower plate voltage. 32 watts.

Got it. I didn't think you were talking about 6L6s in an HXDA.

My HXDA 30 achieves its lower wattage with lower plate voltage as well. Otherwise, it's the same as an HXDA 50. There are times I miss my 50, and then again, there are times I'm really happy I only have to deal with 30 watts.
 
This is exactly what I was talking about. On the back of my 50 watt HXDA head it states "Average bias to 30mV with every tube change and re-bias for 6L6GC, EL34, 6CA7, KT77."
Was just wondering if anyone has tried any of those optional tubes... And what the sonic results were.

Got it. I didn't think you were talking about 6L6s in an HXDA.
 
This is exactly what I was talking about. On the back of my 50 watt HXDA head it states "Average bias to 30mV with every tube change and re-bias for 6L6GC, EL34, 6CA7, KT77."
Was just wondering if anyone has tried any of those optional tubes... And what the sonic results were.

Neither of mine have said that!

Not that it matters much, I really love EL34s in that amp.
 
I think mine is a very early model... I'm not sure. The manufacture date is 11-11 the serial falls in the 110xxx area. What difference if it has the gold bird on the front? I never really got any details on my head...

Neither of mine have said that!

Not that it matters much, I really love EL34s in that amp.
 
Mine was made May 2011 serial number: 110176, (plain black, no bird and white 'recording amp' knobs) and has the same Bias adjustment text as the one on the web retailer's site.

I only wish it had Four EL34's~!
 
The National Obliviousness Department Report

If you look at the picture of the rear panel of this head, you can see the same text under the bias jacks:

http://www.sweetwater.com/store/detail/PRSHXDA

I just checked my HXDA30.

And I feel really foolish, because mine has the very same thing under the bias jacks!

How I could miss this, I will never know, since it's right there for any idiot like me to see...
 
Mine was made May 2011 serial number: 110176, (plain black, no bird and white 'recording amp' knobs) and has the same Bias adjustment text as the one on the web retailer's site.

I only wish it had Four EL34's~!

They make a 100 with 4 EL34s...evidently it even has a half power switch!
 
I just checked my HXDA30.

And I feel really foolish, because mine has the very same thing under the bias jacks!

How I could miss this, I will never know, since it's right there for any idiot like me to see...

No need to feel foolish... you were just too busy enjoying the red hot glass crankin' out a tone that's big as...well...it's big. :hello:
 
Mine was made May 2011 serial number: 110176, (plain black, no bird and white 'recording amp' knobs) and has the same Bias adjustment text as the one on the web retailer's site.

I only wish it had Four EL34's~!

Mine looks just like the link above, with matching 2x12 cabinet. My head is only about 300 behind yours... Guess they are cousins! :cheers:
 
Speaking of tubes, I just scored a lovely set of NOS Siemens EL-34s that I'll install when the Winged Cs that came in the amp wear out. Still working on the right NOS preamp tubes.
 
As a sort of follow up, I got my new preamp tubes, but I keep leaving them at the office....

Any way, my amp has mellowed out a little bit, but now will sound great or "grate" depending on the day/venue/lunar cycle. When it's grating, it's the same sort of spiky, harsh high end that I seem to find on all Marshall 1959/1987 based circuits. The phenomenon is similar to the PRS videos where in Paul's studio the 25th Anniversary and HX/DA amps sound AWESOME, and then I see the video of Tim Pierce demonstrating the HX/DA and it is super harsh.

Honestly, sometimes this amp sounds amazing. I don't get it.

I'm beginning to think maybe I don't like the filtering? Is it power related? What is responsible for that harshness in these circuits? Can it be eliminated?
 
The phenomenon is similar to the PRS videos where in Paul's studio the 25th Anniversary and HX/DA amps sound AWESOME, and then I see the video of Tim Pierce demonstrating the HX/DA and it is super harsh.

Honestly, sometimes this amp sounds amazing. I don't get it.

I'm beginning to think maybe I don't like the filtering? Is it power related? What is responsible for that harshness in these circuits? Can it be eliminated?

My HXDA never sounds harsh. I do think the Tim Pierce video was done with the amp set up poorly, with the master volume way too low, and the gain on the preamp too high for the setting of the master, so all that came through was preamp overdrive. In fact I said so in another thread when the McCarty was introduced in that video; the setup of the amp made the guitar sound less than stellar.

They obviously set it up with that 4x12 cab, which made no sense in that setting, and it seemed to be miked too far off-axis on top of everything.

In contrast, the video in Paul's studio had the master up to a healthy level, and they were actually running a long cable to the cab, and milking the cab in another room. They weren't milking the cab the amp sat on. This is typically how Paul records his studio demos.

i can't of course speak to your custom made amp, since I'm not familiar with it.

In any case, I've recorded my HXDA a lot, and haven't had these issues. I also have a new McCarty and it sounds really nice through my HXDA.
 
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I think mine is a very early model... I'm not sure. The manufacture date is 11-11 the serial falls in the 110xxx area. What difference if it has the gold bird on the front? I never really got any details on my head...
The gold eagle was the Anniversary "badge" and the first HX/DAs were modded Anniversary models, so you have an early model. Do you have smooth rotation master pot or the detented rotary attenuator?

My SuperD is dated 11-06 and is a CAD creation, so there were a lot of great things coming out of the amp department that year.
 
The gold eagle was the Anniversary "badge" and the first HX/DAs were modded Anniversary models, so you have an early model. Do you have smooth rotation master pot or the detented rotary attenuator?

My SuperD is dated 11-06 and is a CAD creation, so there were a lot of great things coming out of the amp department that year.

Actually, all of the HXDAs have the gold eagle. Even the 30Watt version I got a few months ago has it.
 
Actually, all of the HXDAs have the gold eagle. Even the 30Watt version I got a few months ago has it.

No, not all have eagles. My HX/DA does not have the eagle. I think it was made in 2011. I asked about it at the 30th Anniversary event and was just told that most HX/DA amps have the eagle.
 
Only the junky ones! The good ones aren't fragile at all, and last for years.

The old Sinos were the worst of the worst. Very prone to failure.

The Winged Cs that the HXDAs were factory equipped with are in fact SED Winged Cs made in the St. Petersburg Svetlana factory. A different company called New Sensor bought the rights to the Svetlana name marketing, at some point, so SED changed the name to Winged C to be able to market them independently.

The ones currently marked Svetlana aren't as good, in my opinion, they aren't as rich sounding on the low end.

The Winged Cs are in fact very good tubes, and still available on the tube market, though at somewhat higher prices than other recent tubes. If you get them, be sure not to buy from certain vendors who are selling factory seconds. The tube store has an explanation that they only bought firsts, so I'd buy from them.

I can't speak to the Russian Mullard-labeled EL34s. Obviously, they aren't made by Mullard, England, a company that only exists now in name. However, if you want to get very spendy, the original English Mullard EL-34s are available NOS if you look hard enough. Millard often rebranded their tubes for other manufacturers, so many are branded RCA, Phillips, Siemens, Valvo, GE, etc.

The NOS Mullard EL34s last for a very long time, and often have fewer problems than new tubes. Back in the day, players expected their tubes to last a long time. The idea of changing tubes every six months or every year was unheard-of. You ran your tubes until they stopped working or sounded horrible, and that took quite some time!

As an aside, I had 1 1/2 years on my Winged Cs in my HXDA50, and they still sounded fresh. I ran the amp loud. On my current HXDA30, it's only a few months old, but so far, so good. I run it wide open as well.

I was talking to my kids music teacher yesterday and he's mentioned he was changing the in his HXDA and had some English Mullard's to install. He's also going to mod the amp.
 
Yep. Tubes in early '70s amps that you bought used in the '80s lasted for years of gigging! It wasn't until the '90s that I had to replace power tubes with any regularity. Everyone blamed the Chinese back then. If you can find them...and afford them...NOS tubes are a worthy investment.

Fyi, even in my Boogie MkIII, I have had to replace tubes. They are (in)famous for cold-bias'ing their amps, which is much easier in the power tubes. But the power tubes still deplete at an alarming rate, despite the lower voltage. The quality is just poo now.

I have the original tubes in my MKIIC from '83.
 
As a sort of follow up, I got my new preamp tubes, but I keep leaving them at the office....

Any way, my amp has mellowed out a little bit, but now will sound great or "grate" depending on the day/venue/lunar cycle. When it's grating, it's the same sort of spiky, harsh high end that I seem to find on all Marshall 1959/1987 based circuits. The phenomenon is similar to the PRS videos where in Paul's studio the 25th Anniversary and HX/DA amps sound AWESOME, and then I see the video of Tim Pierce demonstrating the HX/DA and it is super harsh.

Honestly, sometimes this amp sounds amazing. I don't get it.

I'm beginning to think maybe I don't like the filtering? Is it power related? What is responsible for that harshness in these circuits? Can it be eliminated?

Depending on the time of day, your amp can/will sound different.
 
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